a$=[[948,34128,67,83,56],[289,819,789,899,672],[429,456]]$

Find minimum digit of every number. Find maximum digit is row. Find their min.

$[948,34128,67,83,56]$ max of $4,1,6,3,5$ is $6$

$[289,819,789,899,672]$ max of $2,1,7,8,2$ is $8$

$[429,456]$ max of $2,4$ is $4.$

min of $6,8,4$ is $4$ Write a python program so that following is outputted

$[[4,2$orless,$6,3$orless,$6$orless:$6],[2,1$orless,$7$:$7$ormore$],[2,4$:$4]]$ output $4$